Thanks for all your WONDERFUL comments and suggestions!!!
Defintely making the choice even HARDER now!
I'll be discussing it with my other sister and will keep you posted on the final result.... (but i have to say, looks like Option A (the Ring) is in the lead!)
We also have a full Intinery planned for her, spanning across the full 24 hours of her birthday! It'll definitely be a day she will never forget! (or forget completely!